| Title: |
Thermal Influence Zone of Energy Tunnels under Different Scenarios in terms of Groundwater Levels and Operation Periods |
| Authors: |
Magdy, Alaaeldin; Di Donna, Alice; Mroueh, Hussein |
| Contributors: |
Laboratoire de Génie Civil et Géo-Environnement (LGCgE) - ULR 4515 (LGCgE); Université d'Artois (UA)-Université de Lille-Ecole nationale supérieure Mines-Télécom Lille Douai (IMT Lille Douai); Institut Mines-Télécom Paris (IMT)-Institut Mines-Télécom Paris (IMT)-JUNIA (JUNIA); Université catholique de Lille (UCL)-Université catholique de Lille (UCL); Laboratoire sols, solides, structures - risques Grenoble (3SR); Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP); Université Grenoble Alpes (UGA); Navier Laboratory, Ecole Nationale des Ponts et Chaussées, Université Gustave Eiffel, CNRS; ANR-22-EXSS-0011,S-PASS,Paris Basin study site – Resources and uses of Urban subsurface(2022) |
| Source: |
3rd International Conference on Energy Geotechnics 2025; https://hal.science/hal-05344055; 3rd International Conference on Energy Geotechnics 2025, Navier Laboratory, Ecole Nationale des Ponts et Chaussées, Université Gustave Eiffel, CNRS, Jun 2025, Paris, France |
| Publisher Information: |
CCSD |
| Publication Year: |
2025 |
| Collection: |
LillOA (HAL Lille Open Archive, Université de Lille) |
| Subject Terms: |
Geothermal energy; groundwater level; thermal influence zone; energy tunnels; energy geostructures; [SPI.GCIV.GEOTECH]Engineering Sciences [physics]/Civil Engineering/Géotechnique |
| Subject Geographic: |
Paris; France |
| Description: |
International audience ; This study explores the thermal influence zone around energy tunnels in sand under the hydrostatic condition over practical thermal operation periods of heating and cooling. Furthermore, it investigates the shape of this zone under different scenarios in terms of groundwater levels (GWLs). A numerical model was developed, validated, and then employed to analyze the extent and shape of the thermal influence zone. The results show that geothermal operations induce changes in groundwater density and viscosity, generating circular groundwater flows that strongly shape the thermal influence zone. In winter, when GWL is close to the tunnel, whether above, at, or just below it, the thermal influence zone forms an oval shape with a lower edge elongation. For example, when GWL is above the tunnel, the thermal influence zone extends downward, reaching about one tunnel diameter (D) below the invert. In summer, the influence zone lacks a specific trend and is notably changed by GWL. For instance, when GWL is above the tunnel, the thermal influence zone extends significantly upward. However, when GWL is at the tunnel centreline, the thermal influence zone takes a horizontal oval shape, which might interfere with adjacent similar installations. In addition, the expansion of the thermal influence zone is highly dependent on the operation period. For example, the downward elongation, in winter, after 6 months reaches around 1.5 times that after 3 months. The study also provides rough estimates for the required clear distance from the tunnel extrados for each thermal operation period. |
| Document Type: |
conference object |
| Language: |
English |
| Availability: |
https://hal.science/hal-05344055; https://hal.science/hal-05344055v1/document; https://hal.science/hal-05344055v1/file/Thermal_Influence_Zone_Extended_abstract.pdf |
| Rights: |
https://about.hal.science/hal-authorisation-v1/ ; info:eu-repo/semantics/OpenAccess |
| Accession Number: |
edsbas.E5EDF5C8 |
| Database: |
BASE |